TW202007077A - Signal gain control method and electronic device - Google Patents

Signal gain control method and electronic device Download PDF

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TW202007077A
TW202007077A TW107123984A TW107123984A TW202007077A TW 202007077 A TW202007077 A TW 202007077A TW 107123984 A TW107123984 A TW 107123984A TW 107123984 A TW107123984 A TW 107123984A TW 202007077 A TW202007077 A TW 202007077A
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impedance
signal
external device
adjustment value
gain adjustment
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TW107123984A
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TWI658693B (en
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戴魁廷
張嘉仁
游明春
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宏碁股份有限公司
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G3/00—Gain control in amplifiers or frequency changers
    • H03G3/20—Automatic control
    • H03G3/30—Automatic control in amplifiers having semiconductor devices
    • H03G3/3005—Automatic control in amplifiers having semiconductor devices in amplifiers suitable for low-frequencies, e.g. audio amplifiers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
    • G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G2201/00—Indexing scheme relating to subclass H03G
    • H03G2201/10—Gain control characterised by the type of controlled element
    • H03G2201/103—Gain control characterised by the type of controlled element being an amplifying element

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Amplifiers (AREA)
  • Circuit For Audible Band Transducer (AREA)

Abstract

A signal gain control method for an electronic device including an alternating-current (AC) impedance detector and a direct-current (DC) impedance detector is provided according to an embodiment of the disclosure and the electronic device is coupled to an external device. The method includes: detecting an AC impedance of the external device by the AC impedance detector; detecting a DC impedance of the external device by the DC impedance detector; obtaining a gain adjustment value according to the AC impedance and the DC impedance; and adjusting a signal gain of an audio signal output to the external device according to the gain adjustment value. In addition, an electronic device is also provided according to an embodiment of the disclosure.

Description

訊號增益控制方法與電子裝置Signal gain control method and electronic device

本發明是有關於一種訊號調整技術，且特別是有關於一種訊號增益控制方法與電子裝置。The invention relates to a signal adjustment technology, and in particular to a signal gain control method and an electronic device.

隨著科技的進步，消費者越來越注重多媒體娛樂裝置的音訊輸出品質。然而，不同的外接音訊輸出裝置可能有不同的阻抗特性。因此，當使用不同的外接音訊輸出裝置連接同一多媒體娛樂裝置時，可能會導致不同的外接音訊輸出裝置的音訊播放品質時好時壞。With the advancement of technology, consumers are paying more and more attention to the audio output quality of multimedia entertainment devices. However, different external audio output devices may have different impedance characteristics. Therefore, when different external audio output devices are used to connect to the same multimedia entertainment device, the audio playback quality of different external audio output devices may be good or bad.

本發明提供一種訊號增益控制方法與電子裝置，可偵測外接裝置的交流阻抗並據以調整輸出訊號的訊號增益，從而使外接裝置的音訊播放品質保持良好且穩定。The invention provides a signal gain control method and an electronic device, which can detect the AC impedance of an external device and adjust the signal gain of the output signal accordingly, so that the audio playback quality of the external device remains good and stable.

本發明實施例提供一種訊號增益控制方法，其用於包括交流阻抗偵測器與直流阻抗偵測器的電子裝置，所述電子裝置連接至外接裝置。所述訊號增益控制方法包括：由所述交流阻抗偵測器偵測所述外接裝置的交流阻抗；由所述直流阻抗偵測器偵測所述外接裝置的直流阻抗；根據所述交流阻抗與所述直流阻抗獲得增益調整值；以及根據所述增益調整值調整輸出至所述外接裝置的輸出訊號的訊號增益。An embodiment of the present invention provides a signal gain control method for an electronic device including an AC impedance detector and a DC impedance detector, the electronic device being connected to an external device. The signal gain control method includes: detecting the AC impedance of the external device by the AC impedance detector; detecting the DC impedance of the external device by the DC impedance detector; according to the AC impedance and The DC impedance obtains a gain adjustment value; and adjusts the signal gain of the output signal output to the external device according to the gain adjustment value.

本發明實施例另提供一種電子裝置，其連接至外接裝置。所述電子裝置包括交流阻抗偵測器、直流阻抗偵測器、訊號處理電路及增益控制電路。所述交流阻抗偵測器用以偵測所述外接裝置的交流阻抗。所述直流阻抗偵測器用以偵測所述外接裝置的直流阻抗。所述訊號處理電路連接至所述交流阻抗偵測器與所述直流阻抗偵測器並且用以根據所述交流阻抗與所述直流阻抗獲得增益調整值。所述增益控制電路連接至所述訊號處理電路並且用以根據所述增益調整值調整輸出至所述外接裝置的輸出訊號的訊號增益。An embodiment of the present invention further provides an electronic device, which is connected to an external device. The electronic device includes an AC impedance detector, a DC impedance detector, a signal processing circuit and a gain control circuit. The AC impedance detector is used to detect the AC impedance of the external device. The DC impedance detector is used to detect the DC impedance of the external device. The signal processing circuit is connected to the AC impedance detector and the DC impedance detector and used to obtain a gain adjustment value according to the AC impedance and the DC impedance. The gain control circuit is connected to the signal processing circuit and used to adjust the signal gain of the output signal output to the external device according to the gain adjustment value.

基於上述，在偵測外接裝置的交流阻抗與直流阻抗後，一個增益調整值可根據此交流阻抗與直流阻抗而獲得。接著，此增益調整值可用於調整輸出至外接裝置的輸出訊號的訊號增益，從而使外接裝置的音訊播放品質保持良好且穩定。Based on the above, after detecting the AC impedance and the DC impedance of the external device, a gain adjustment value can be obtained according to the AC impedance and the DC impedance. Then, the gain adjustment value can be used to adjust the signal gain of the output signal output to the external device, so that the audio playback quality of the external device remains good and stable.

為讓本發明的上述特徵和優點能更明顯易懂，下文特舉實施例，並配合所附圖式作詳細說明如下。In order to make the above-mentioned features and advantages of the present invention more obvious and understandable, the embodiments are specifically described below in conjunction with the accompanying drawings for detailed description as follows.

圖1是根據本發明的一實施例所繪示的電子裝置與外接裝置的示意圖。請參照圖1，電子裝置10可以是智慧型手機、平板電腦、桌上型電腦、筆記型電腦、電視機、機頂盒、遊戲機或顯示器等具音訊輸出功能的多媒體娛樂裝置。外接裝置11連接至電子裝置10。外接裝置11為喇叭或耳機等音訊播放裝置，用以將電子裝置10提供的音訊訊號轉換為聲音而輸出。在以下實施例中，是以耳機作為外接裝置11的範例。FIG. 1 is a schematic diagram of an electronic device and an external device according to an embodiment of the invention. Referring to FIG. 1, the electronic device 10 may be a multimedia entertainment device with audio output function such as a smart phone, tablet computer, desktop computer, notebook computer, television, set-top box, game console, or display. The external device 11 is connected to the electronic device 10. The external device 11 is an audio playback device such as a speaker or headphones, which is used to convert the audio signal provided by the electronic device 10 into sound and output it. In the following embodiments, the earphone is used as an example of the external device 11.

在本實施例中，電子裝置10包括音訊輸入電路101、訊號處理電路102、增益控制電路103、驅動電路104、連接介面105、直流(Direct-Current, DC)阻抗偵測器106、交流(Alternating-Current, AC)阻抗偵測器107及連接偵測器108。In this embodiment, the electronic device 10 includes an audio input circuit 101, a signal processing circuit 102, a gain control circuit 103, a driving circuit 104, a connection interface 105, a direct current (DC) impedance detector 106, and an alternating current (Alternating) -Current, AC) impedance detector 107 and connection detector 108.

音訊輸入電路101用以接收訊號S1。訊號S1為音訊訊號並可由電子裝置10的音訊晶片(未繪示)或中央處理器(未繪示)等內部電路提供。音訊輸入電路101可包括類比數位轉換器(Analog-to-Digital converter, ADC)(未繪示)與等化器(未繪示)。音訊輸入電路101可執行訊號的類比數位轉換、通道補償及/或雜訊濾除等操作。The audio input circuit 101 is used to receive the signal S1. The signal S1 is an audio signal and can be provided by an internal circuit such as an audio chip (not shown) or a central processing unit (not shown) of the electronic device 10. The audio input circuit 101 may include an analog-to-digital converter (ADC) (not shown) and an equalizer (not shown). The audio input circuit 101 can perform analog digital conversion of signals, channel compensation, and/or noise filtering.

訊號處理電路102可包括數位訊號處理器(Digital Signal Processor, DSP)或類似電路。連接介面105用以連接外接裝置11。例如，連接介面105可支援各式耳機孔(例如3.5mm耳機孔)或通用序列匯流排(USB)等連接介面標準。The signal processing circuit 102 may include a digital signal processor (Digital Signal Processor, DSP) or similar circuit. The connection interface 105 is used to connect to the external device 11. For example, the connection interface 105 can support various types of connection interface standards such as various types of earphone jacks (such as 3.5mm headphone jacks) or universal serial bus (USB).

連接偵測器108連接至訊號處理電路102與連接介面105並且用以偵測外接裝置11是否與連接介面105電性連接。例如，當外接裝置11的訊號傳輸線插頭插入至電子裝置10的耳機孔時，連接偵測器108可產生一個訊號ON至訊號處理電路102，以通知訊號處理電路102外接裝置11已經由連接介面105電性連接至電子裝置10。換言之，訊號ON反映外接裝置11已電性連接至連接介面105。當外接裝置11的訊號傳輸線插頭從電子裝置10的耳機孔移除時，連接偵測器108可產生一個訊號OFF至訊號處理電路102，以通知訊號處理電路102外接裝置11已與連接介面105電性分離。換言之，訊號OFF反映外接裝置11已與連接介面105電性分離。The connection detector 108 is connected to the signal processing circuit 102 and the connection interface 105 and is used to detect whether the external device 11 is electrically connected to the connection interface 105. For example, when the signal transmission line plug of the external device 11 is inserted into the headphone jack of the electronic device 10, the connection detector 108 can generate a signal ON to the signal processing circuit 102 to notify the signal processing circuit 102 that the external device 11 has been connected by the connection interface 105 Electrically connected to the electronic device 10. In other words, the signal ON reflects that the external device 11 has been electrically connected to the connection interface 105. When the signal transmission line plug of the external device 11 is removed from the headphone jack of the electronic device 10, the connection detector 108 can generate a signal OFF to the signal processing circuit 102 to notify the signal processing circuit 102 that the external device 11 has connected to the connection interface 105 Sexual separation. In other words, the signal OFF reflects that the external device 11 has been electrically separated from the connection interface 105.

直流阻抗偵測器106連接至訊號處理電路102與連接介面105並且用以偵測外接裝置11的直流阻抗並將訊號RDC傳送給訊號處理電路102。訊號RDC反映外接裝置11的直流阻抗。例如，直流阻抗偵測器106可經由連接介面105偵測外接裝置11的電壓與電流。直流阻抗偵測器106可根據此電壓與電流獲得外接裝置11的直流阻抗。The DC impedance detector 106 is connected to the signal processing circuit 102 and the connection interface 105 and is used to detect the DC impedance of the external device 11 and transmit the signal RDC to the signal processing circuit 102. The signal RDC reflects the DC impedance of the external device 11. For example, the DC impedance detector 106 can detect the voltage and current of the external device 11 through the connection interface 105. The DC impedance detector 106 can obtain the DC impedance of the external device 11 according to the voltage and current.

交流阻抗偵測器107連接至訊號處理電路102與連接介面105並且用以偵測外接裝置11的交流阻抗並將訊號RAC傳送給訊號處理電路102。訊號RAC反映外接裝置11的交流阻抗。The AC impedance detector 107 is connected to the signal processing circuit 102 and the connection interface 105 and is used to detect the AC impedance of the external device 11 and transmit the signal RAC to the signal processing circuit 102. The signal RAC reflects the AC impedance of the external device 11.

在一實施例中，交流阻抗偵測器107可經由連接介面105發送掃頻訊號至外接裝置11。此掃頻訊號的頻率在一預定頻率範圍(例如10Hz~10KHz)內變化。根據所發出之掃頻訊號，交流阻抗偵測器107可獲得外接裝置11的交流阻抗。例如，根據掃頻訊號的頻率變化，交流阻抗偵測器107可測得在一數值範圍內變化的多個阻抗(亦稱為候選交流阻抗)。然後，交流阻抗偵測器107可記錄此些候選交流阻抗並根據其中的最大值獲得外接裝置11的交流阻抗。例如，交流阻抗偵測器107可將此些候選交流阻抗的最大值決定為外接裝置11的交流阻抗。此外，候選交流阻抗的最小值可相同或趨近直流阻抗偵測器106所測得的直流阻抗。In one embodiment, the AC impedance detector 107 can send a frequency sweep signal to the external device 11 via the connection interface 105. The frequency of the sweep signal changes within a predetermined frequency range (for example, 10 Hz to 10 KHz). According to the transmitted frequency sweep signal, the AC impedance detector 107 can obtain the AC impedance of the external device 11. For example, according to the frequency change of the sweep signal, the AC impedance detector 107 can measure a plurality of impedances (also referred to as candidate AC impedances) that vary within a range of values. Then, the AC impedance detector 107 may record these candidate AC impedances and obtain the AC impedance of the external device 11 according to the maximum value. For example, the AC impedance detector 107 may determine the maximum value of these candidate AC impedances as the AC impedance of the external device 11. In addition, the minimum value of the candidate AC impedance may be the same or approach the DC impedance measured by the DC impedance detector 106.

圖2是根據本發明的一實施例所繪示的交流阻抗的示意圖。請參照圖1與圖2，在發出掃頻訊號後，響應於掃頻訊號的頻率變化，交流阻抗偵測器107所測得的阻抗(即候選交流阻抗)在數值32與33之間變化。其中，數值33為候選交流阻抗的最大值，而數值32為候選交流阻抗的最小值，如圖2所示。FIG. 2 is a schematic diagram of AC impedance according to an embodiment of the invention. Please refer to FIGS. 1 and 2. After sending the sweep signal, in response to the frequency change of the sweep signal, the impedance measured by the AC impedance detector 107 (that is, the candidate AC impedance) changes between 32 and 33. Among them, the value 33 is the maximum value of the candidate AC impedance, and the value 32 is the minimum value of the candidate AC impedance, as shown in FIG. 2.

在本實施例中，交流阻抗偵測器107可將數值33(即33歐姆)設為外接裝置11的交流阻抗並經由訊號RAC通知訊號處理電路102。此外，在本實施例中，候選交流阻抗的最小值(例如32歐姆)可相同或趨近直流阻抗偵測器106所測得的直流阻抗。In this embodiment, the AC impedance detector 107 may set the value 33 (ie, 33 ohms) to the AC impedance of the external device 11 and notify the signal processing circuit 102 via the signal RAC. In addition, in this embodiment, the minimum value of the candidate AC impedance (for example, 32 ohms) may be the same or approach the DC impedance measured by the DC impedance detector 106.

圖3是根據本發明的另一實施例所繪示的交流阻抗的示意圖。請參照圖1與圖3，在發出掃頻訊號後，響應於掃頻訊號的頻率變化，交流阻抗偵測器107所測得的阻抗(即候選交流阻抗)在數值32與48之間變化。其中，數值48為候選交流阻抗的最大值，而數值32為候選交流阻抗的最小值，如圖3所示。FIG. 3 is a schematic diagram of an AC impedance according to another embodiment of the invention. Please refer to FIGS. 1 and 3. After sending the sweep signal, in response to the frequency change of the sweep signal, the impedance measured by the AC impedance detector 107 (that is, the candidate AC impedance) changes between 32 and 48. Among them, the value 48 is the maximum value of the candidate AC impedance, and the value 32 is the minimum value of the candidate AC impedance, as shown in FIG. 3.

在本實施例中，交流阻抗偵測器107可將數值48(即48歐姆)設為外接裝置11的交流阻抗並經由訊號RAC通知訊號處理電路102。此外，在本實施例中，候選交流阻抗的最小值(例如32歐姆)同樣可相同或趨近直流阻抗偵測器106所測得的直流阻抗。In this embodiment, the AC impedance detector 107 may set the value 48 (ie, 48 ohms) to the AC impedance of the external device 11 and notify the signal processing circuit 102 via the signal RAC. In addition, in this embodiment, the minimum value of the candidate AC impedance (for example, 32 ohms) can also be the same or approach the DC impedance measured by the DC impedance detector 106.

在根據訊號ON判定外接裝置11已連接至連接介面105後，訊號處理電路102可根據訊號RDC與訊號RAC獲得一個增益調整值。訊號處理電路102可根據此增益調整值指示增益控制電路103調整用於訊號S1的訊號增益。After determining that the external device 11 has been connected to the connection interface 105 according to the signal ON, the signal processing circuit 102 can obtain a gain adjustment value according to the signal RDC and the signal RAC. The signal processing circuit 102 can instruct the gain control circuit 103 to adjust the signal gain for the signal S1 according to the gain adjustment value.

在一實施例中，增益控制電路103亦稱為耳機增益控制器。增益控制電路103連接至音訊輸入電路101與訊號處理電路102。增益控制電路103用以根據訊號處理電路102的指示使用相應的增益調整值來對通過音訊輸入電路101的訊號S1執行增益補償。然後，驅動電路104可根據增益控制電路103的輸出產生訊號S2並經由連接介面105將訊號S2提供至外接裝置11。外接裝置11可根據訊號S2執行音訊播放操作以輸出聲音(例如音樂)。In an embodiment, the gain control circuit 103 is also called a headphone gain controller. The gain control circuit 103 is connected to the audio input circuit 101 and the signal processing circuit 102. The gain control circuit 103 is used to perform gain compensation on the signal S1 passing through the audio input circuit 101 using a corresponding gain adjustment value according to the instruction of the signal processing circuit 102. Then, the driving circuit 104 can generate the signal S2 according to the output of the gain control circuit 103 and provide the signal S2 to the external device 11 via the connection interface 105. The external device 11 can perform an audio playback operation according to the signal S2 to output sound (such as music).

在一實施例中，電子裝置10還包括雜音消除器109。雜音消除器109連接至訊號處理電路102與驅動電路104。雜音消除器109可根據訊號處理電路102的指示產生雜音消除訊號。驅動電路104可根據此雜音消除訊號減少訊號S2中的雜音成分(例如背景雜音或雜訊引起的雜音)。In an embodiment, the electronic device 10 further includes a noise canceller 109. The noise canceller 109 is connected to the signal processing circuit 102 and the driving circuit 104. The noise canceller 109 can generate a noise canceling signal according to the instruction of the signal processing circuit 102. The driving circuit 104 can reduce noise components (such as background noise or noise caused by noise) in the signal S2 according to the noise cancellation signal.

在一實施例中，候選交流阻抗的最大值(及/或候選交流阻抗的最大值與最小值之間的差值)會正相關於外接裝置11之揚聲器的感度。亦即，若外接裝置11之揚聲器的感度越高，則外接裝置11輸出的聲音音量較容易增加。反之，若外接裝置11之揚聲器的感度越低，則外接裝置11輸出的聲音音量較不容易增加。In an embodiment, the maximum value of the candidate AC impedance (and/or the difference between the maximum value and the minimum value of the candidate AC impedance) is positively related to the sensitivity of the speaker of the external device 11. That is, if the sensitivity of the speaker of the external device 11 is higher, the volume of sound output by the external device 11 is easier to increase. Conversely, if the sensitivity of the speaker of the external device 11 is lower, the volume of the sound output by the external device 11 is less likely to increase.

以圖2與圖3為例，圖3的實施例中候選交流組抗的最大值(即48歐姆)大於圖2的實施例中候選交流組抗的最大值(即33歐姆)，及/或圖3的實施例中候選交流組抗的最大值與最小值之間的差值R2(即16歐姆)大於圖2的實施例中候選交流組抗的最大值與最小值之間的差值R1(即1歐姆)，表示圖3的實施例中外接裝置11之揚聲器的感度可能高於圖2的實施例中外接裝置11之揚聲器的感度。因此，若圖3的實施例中用於訊號S1的訊號增益小於圖2的實施例中用於訊號S1的訊號增益的訊號增益，可提高外接裝置11的音訊播放品質。Taking FIGS. 2 and 3 as examples, the maximum value of the candidate AC impedance in the embodiment of FIG. 3 (that is, 48 ohms) is greater than the maximum value of the candidate AC impedance in the embodiment of FIG. 2 (that is, 33 ohms), and/or The difference R2 (ie, 16 ohms) between the maximum and minimum values of the candidate AC impedance in the embodiment of FIG. 3 is greater than the difference R1 between the maximum and minimum values of the candidate AC impedance in the embodiment of FIG. 2 (Ie, 1 ohm), indicating that the sensitivity of the speaker of the external device 11 in the embodiment of FIG. 3 may be higher than the sensitivity of the speaker of the external device 11 in the embodiment of FIG. 2. Therefore, if the signal gain for the signal S1 in the embodiment of FIG. 3 is smaller than the signal gain for the signal S1 in the embodiment of FIG. 2, the audio playback quality of the external device 11 can be improved.

在一實施例中，訊號處理電路102可根據外接裝置11的交流阻抗與外接裝置11的直流阻抗之間的差值獲得所述增益調整值。例如，在圖2的實施例中，訊號處理電路102可根據差值R1決定一個增益調整值(亦稱為第一增益調整值)並指示增益控制電路103根據第一增益調整值對訊號S1執行增益補償；在圖3的實施例中，訊號處理電路102可根據差值R2決定另一個增益調整值(亦稱為第二增益調整值)並指示增益控制電路103根據第二增益調整值對訊號S1執行增益補償。第二增益調整值會小於第一增益調整值。藉此，可使得圖3的實施例中用於訊號S1的訊號增益小於圖2的實施例中用於訊號S1的訊號增益的訊號增益，從而提高外接裝置11的音訊播放品質。In an embodiment, the signal processing circuit 102 may obtain the gain adjustment value according to the difference between the AC impedance of the external device 11 and the DC impedance of the external device 11. For example, in the embodiment of FIG. 2, the signal processing circuit 102 may determine a gain adjustment value (also referred to as a first gain adjustment value) according to the difference R1 and instruct the gain control circuit 103 to execute the signal S1 according to the first gain adjustment value Gain compensation; in the embodiment of FIG. 3, the signal processing circuit 102 can determine another gain adjustment value (also called a second gain adjustment value) according to the difference R2 and instruct the gain control circuit 103 to adjust the signal according to the second gain adjustment value S1 performs gain compensation. The second gain adjustment value will be smaller than the first gain adjustment value. In this way, the signal gain for the signal S1 in the embodiment of FIG. 3 can be made smaller than the signal gain for the signal S1 in the embodiment of FIG. 2, thereby improving the audio playback quality of the external device 11.

在一實施例中，訊號處理電路102可根據外接裝置11的直流阻抗決定一個初始增益調整值。例如，訊號處理電路102可根據以下方程式(1)獲得初始增益調整值。In one embodiment, the signal processing circuit 102 may determine an initial gain adjustment value according to the DC impedance of the external device 11. For example, the signal processing circuit 102 may obtain the initial gain adjustment value according to the following equation (1).

Figure 02_image001
(1)
Figure 02_image001
(1)

在方程式(1)中，參數G表示初始增益調整值，參數Rhs表示預設的阻抗，參數Rhs1表示新連接的外接裝置11的直流阻抗，Z為線路上的串接阻抗。In equation (1), the parameter G represents the initial gain adjustment value, the parameter Rhs represents the preset impedance, the parameter Rhs1 represents the DC impedance of the newly connected external device 11, and Z is the series impedance on the line.

在一實施例中，訊號處理電路102可根據外接裝置11的交流阻抗與外接裝置11的直流阻抗之間的差值，來調整初始增益調整值以獲得所述增益調整值。例如，訊號處理電路102可判斷外接裝置11的交流阻抗與外接裝置11的直流阻抗之間的差值是否大於一個門檻值。若所述差值不大於此門檻值，訊號處理電路102可指示增益控制電路103直接根據此初始增益調整值對訊號S1執行增益補償。然而，若所述差值大於此門檻值(表示外接裝置11的感度較高)，訊號處理電路102可產生一個微調值並根據此微調值來調整初始增益調整值以獲得所述增益調整值。例如，在產生微調值後，訊號處理電路102可將初始增益調整值減去此微調值而獲得所述增益調整值，以降低用於訊號S1的增益補償。然後，訊號處理電路102可指示增益控制電路103根據調整後的增益調整值對訊號S1執行增益補償。In one embodiment, the signal processing circuit 102 may adjust the initial gain adjustment value according to the difference between the AC impedance of the external device 11 and the DC impedance of the external device 11 to obtain the gain adjustment value. For example, the signal processing circuit 102 can determine whether the difference between the AC impedance of the external device 11 and the DC impedance of the external device 11 is greater than a threshold. If the difference is not greater than the threshold value, the signal processing circuit 102 may instruct the gain control circuit 103 to directly perform gain compensation on the signal S1 according to the initial gain adjustment value. However, if the difference is greater than this threshold (indicating that the sensitivity of the external device 11 is higher), the signal processing circuit 102 may generate a fine adjustment value and adjust the initial gain adjustment value according to the fine adjustment value to obtain the gain adjustment value. For example, after generating the fine adjustment value, the signal processing circuit 102 may subtract the fine adjustment value from the initial gain adjustment value to obtain the gain adjustment value to reduce the gain compensation for the signal S1. Then, the signal processing circuit 102 may instruct the gain control circuit 103 to perform gain compensation on the signal S1 according to the adjusted gain adjustment value.

以下以圖2與圖3為例進行說明，並假設門檻值為8。在圖2的實施例中，差值R1(即1)小於門檻值(即8)，故訊號處理電路102可指示增益控制電路103直接根據初始增益調整值對訊號S1執行增益補償，而可不對初始增益調整值進行微調。然而，在圖3的實施例中，差值R2(即16)大於門檻值(即8)，故訊號處理電路102可先將初始增益調整值減去一個微調值以獲得增益調整值。然後，訊號處理電路102可指示根據調整後的增益調整值對訊號S1執行增益補償。藉此，無論當前連接的外接裝置11為高感度或低感度的音訊播放裝置，訊號處理電路102皆可動態決定適當的增益調整值來對輸出至外接裝置11的音訊訊號執行增益補償，使得外接裝置的音訊播放品質保持良好且穩定。The following uses FIG. 2 and FIG. 3 as examples for explanation, and assumes that the threshold value is 8. In the embodiment of FIG. 2, the difference R1 (ie, 1) is less than the threshold (ie, 8), so the signal processing circuit 102 can instruct the gain control circuit 103 to directly perform gain compensation on the signal S1 according to the initial gain adjustment value, but not Fine-tune the initial gain adjustment value. However, in the embodiment of FIG. 3, the difference R2 (ie, 16) is greater than the threshold value (ie, 8), so the signal processing circuit 102 may first subtract a fine adjustment value from the initial gain adjustment value to obtain the gain adjustment value. Then, the signal processing circuit 102 may instruct to perform gain compensation on the signal S1 according to the adjusted gain adjustment value. Thereby, regardless of whether the currently connected external device 11 is a high-sensitivity or low-sensitivity audio playback device, the signal processing circuit 102 can dynamically determine an appropriate gain adjustment value to perform gain compensation on the audio signal output to the external device 11, so that the external The audio playback quality of the device remains good and stable.

在一實施例中，訊號處理電路102還可根據外接裝置11的直流阻抗調整訊號S2的輸出電壓區間。例如，在獲得外接裝置11的直流阻抗後，訊號處理電路102可根據此直流阻抗查詢一個電壓區間表格。例如，此電壓區間表格可記載多個直流阻抗所分別對應的輸出電壓區間。根據此電壓區間表格，訊號處理電路102可獲得外接裝置11的直流阻抗所對應的輸出電壓區間。若當前偵測到的電壓不同於此輸出電壓區間，訊號處理電路102可經由增益控制電路103與驅動電路104將訊號S2的電壓調整至此輸出電壓區間內。反之，若前偵測到的電壓已符合此輸出電壓區間，則訊號S2的電壓可不被調整。In one embodiment, the signal processing circuit 102 can also adjust the output voltage interval of the signal S2 according to the DC impedance of the external device 11. For example, after obtaining the DC impedance of the external device 11, the signal processing circuit 102 may query a voltage interval table according to the DC impedance. For example, the voltage interval table may record output voltage intervals corresponding to a plurality of DC impedances. According to this voltage interval table, the signal processing circuit 102 can obtain the output voltage interval corresponding to the DC impedance of the external device 11. If the currently detected voltage is different from the output voltage interval, the signal processing circuit 102 can adjust the voltage of the signal S2 to the output voltage interval through the gain control circuit 103 and the driving circuit 104. Conversely, if the previously detected voltage has met this output voltage range, the voltage of signal S2 may not be adjusted.

圖4是根據本發明的一實施例所繪示的訊號增益控制方法的流程圖。請參照圖4，在步驟S401中，由交流阻抗偵測器偵測外接裝置的交流阻抗。在步驟S402中，由直流阻抗偵測器偵測外接裝置的直流阻抗。在步驟S403中，根據所述交流阻抗與所述直流阻抗獲得增益調整值。在步驟S404中，根據所述增益調整值調整輸出至所述外接裝置的輸出訊號(即音訊訊號)的訊號增益。4 is a flowchart of a signal gain control method according to an embodiment of the invention. Referring to FIG. 4, in step S401, the AC impedance of the external device is detected by the AC impedance detector. In step S402, the DC impedance of the external device is detected by the DC impedance detector. In step S403, a gain adjustment value is obtained according to the AC impedance and the DC impedance. In step S404, the signal gain of the output signal (ie, audio signal) output to the external device is adjusted according to the gain adjustment value.

圖5是根據本發明的一實施例所繪示的訊號增益控制方法的流程圖。請參照圖5，在步驟S501中，經由連接介面連接外接裝置。在步驟S502中，經由連接介面偵測電壓與電流。在步驟S503中，根據所偵測的電壓與電流獲得外接裝置的直流阻抗。在步驟S504中，根據外接裝置的直流阻抗判斷是否調整訊號的輸出電壓區間。若需調整訊號的輸出電壓區間，在步驟S505中，調整訊號的輸出電壓區間。若不需調整訊號的輸出電壓區間，在步驟S506中，根據直流阻抗獲得增益調整值(即初始增益調整值)。5 is a flowchart of a signal gain control method according to an embodiment of the invention. Please refer to FIG. 5. In step S501, an external device is connected via a connection interface. In step S502, the voltage and current are detected via the connection interface. In step S503, the DC impedance of the external device is obtained according to the detected voltage and current. In step S504, it is determined whether to adjust the output voltage interval of the signal according to the DC impedance of the external device. If the output voltage interval of the signal needs to be adjusted, in step S505, the output voltage interval of the signal is adjusted. If there is no need to adjust the output voltage interval of the signal, in step S506, a gain adjustment value (ie, an initial gain adjustment value) is obtained according to the DC impedance.

另一方面，在步驟S507中，發送掃頻訊號，其頻率會在一預設頻率範圍內改變。在步驟S508中，根據所述掃頻訊號獲得外接裝置的交流阻抗。在步驟S509中，判斷直流阻抗與交流阻抗之間的差值是否大於門檻值。若直流阻抗與交流阻抗之間的差值大於門檻值，在步驟S510中，調整增益調整值。例如，減少初始增益調整值。若直流阻抗與交流阻抗之間的差值不大於門檻值，可直接進入步驟S511。在步驟S511中，根據(調整後的)增益調整值調整音訊訊號。On the other hand, in step S507, the frequency sweep signal is sent, and its frequency will change within a preset frequency range. In step S508, the AC impedance of the external device is obtained according to the frequency sweep signal. In step S509, it is determined whether the difference between the DC impedance and the AC impedance is greater than the threshold. If the difference between the DC impedance and the AC impedance is greater than the threshold, in step S510, the gain adjustment value is adjusted. For example, reduce the initial gain adjustment value. If the difference between the DC impedance and the AC impedance is not greater than the threshold value, step S511 can be directly entered. In step S511, the audio signal is adjusted according to the (adjusted) gain adjustment value.

須注意的是，圖4與圖5中各步驟已詳細說明如上，在此便不再贅述。圖4與圖5中各步驟可以實作為多個程式碼或是電路，本發明不加以限制。此外，圖4與圖5的方法可以搭配以上範例實施例使用，也可以單獨使用，本發明不加以限制。It should be noted that the steps in FIGS. 4 and 5 have been described in detail above, and will not be repeated here. The steps in FIGS. 4 and 5 can be implemented as multiple codes or circuits, and the invention is not limited thereto. In addition, the methods of FIG. 4 and FIG. 5 can be used in conjunction with the above exemplary embodiments, or can be used alone, the invention is not limited.

綜上所述，本發明實施例在偵測外接裝置的交流阻抗與直流阻抗後，一個增益調整值可根據此交流阻抗與直流阻抗而獲得。接著，此增益調整值可用於調整輸出至外接裝置的輸出訊號的訊號增益。特別是，在考量了外接裝置的交流阻抗後，無論當前連接的外接裝置為高感度或低感度的音訊播放裝置，本發明實施例皆可動態決定適當的增益調整值來對輸出至外接裝置的音訊訊號執行增益補償，從而使外接裝置的音訊播放品質保持良好且穩定。In summary, after detecting the AC impedance and the DC impedance of the external device, a gain adjustment value can be obtained according to the AC impedance and the DC impedance. Then, the gain adjustment value can be used to adjust the signal gain of the output signal output to the external device. In particular, after considering the AC impedance of the external device, regardless of whether the currently connected external device is a high-sensitivity or low-sensitivity audio playback device, the embodiments of the present invention can dynamically determine an appropriate gain adjustment value for output to the external device. The audio signal performs gain compensation so that the audio playback quality of the external device remains good and stable.

雖然本發明已以實施例揭露如上，然其並非用以限定本發明，任何所屬技術領域中具有通常知識者，在不脫離本發明的精神和範圍內，當可作些許的更動與潤飾，故本發明的保護範圍當視後附的申請專利範圍所界定者為準。Although the present invention has been disclosed as above with examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be subject to the scope defined in the appended patent application.

10‧‧‧電子裝置11‧‧‧外接裝置101‧‧‧音訊輸入電路102‧‧‧訊號處理電路103‧‧‧增益控制電路104‧‧‧驅動電路105‧‧‧連接介面106‧‧‧直流阻抗偵測器107‧‧‧交流阻抗偵測器108‧‧‧連接偵測器109‧‧‧雜音消除器S1、S2、RDC、RAC、ON/OFF‧‧‧訊號S401~S404、S501~S511‧‧‧步驟10‧‧‧Electronic device 11‧‧‧External device 101‧‧‧Audio input circuit 102‧‧‧Signal processing circuit 103‧‧‧Gain control circuit 104‧‧‧Drive circuit 105‧‧‧Connection interface 106‧‧‧DC Impedance Detector 107‧‧‧AC Impedance Detector 108‧‧‧ Connected Detector 109‧‧‧ Noise Eliminator S1, S2, RDC, RAC, ON/OFF‧ Signals S401~S404, S501~S511 ‧‧‧step

圖1是根據本發明的一實施例所繪示的電子裝置與外接裝置的示意圖。 圖2是根據本發明的一實施例所繪示的交流阻抗的示意圖。 圖3是根據本發明的另一實施例所繪示的交流阻抗的示意圖。 圖4是根據本發明的一實施例所繪示的訊號增益控制方法的流程圖。 圖5是根據本發明的一實施例所繪示的訊號增益控制方法的流程圖。FIG. 1 is a schematic diagram of an electronic device and an external device according to an embodiment of the invention. FIG. 2 is a schematic diagram of AC impedance according to an embodiment of the invention. FIG. 3 is a schematic diagram of an AC impedance according to another embodiment of the invention. 4 is a flowchart of a signal gain control method according to an embodiment of the invention. 5 is a flowchart of a signal gain control method according to an embodiment of the invention.

S401~S404‧‧‧步驟 S401~S404‧‧‧Step

Claims (11)

一種訊號增益控制方法，用於一電子裝置，其中該電子裝置包括一交流阻抗偵測器與一直流阻抗偵測器，該電子裝置連接至一外接裝置，且該訊號增益控制方法包括： 由該交流阻抗偵測器偵測該外接裝置的一交流阻抗； 由該直流阻抗偵測器偵測該外接裝置的一直流阻抗； 根據該交流阻抗與該直流阻抗獲得一增益調整值；以及 根據該增益調整值調整輸出至該外接裝置的一音訊訊號的一訊號增益。A signal gain control method for an electronic device, wherein the electronic device includes an AC impedance detector and a DC impedance detector, the electronic device is connected to an external device, and the signal gain control method includes: The AC impedance detector detects an AC impedance of the external device; the DC impedance detector detects the DC impedance of the external device; a gain adjustment value is obtained according to the AC impedance and the DC impedance; and according to the gain The adjustment value adjusts a signal gain of an audio signal output to the external device. 如申請專利範圍第1項所述的訊號增益控制方法，其中由該交流阻抗偵測器偵測該外接裝置的該交流阻抗的步驟包括： 發送一掃頻訊號，其中該掃頻訊號的頻率在一頻率範圍內變化； 根據該掃頻訊號的一頻率變化測得對應於該外接裝置的多個候選交流阻抗；以及 根據該多個候選交流阻抗的一最大值獲得該交流阻抗。The signal gain control method as described in item 1 of the patent application range, wherein the step of detecting the AC impedance of the external device by the AC impedance detector includes: sending a sweep signal, wherein the frequency of the sweep signal is at Changes within the frequency range; measuring a plurality of candidate AC impedances corresponding to the external device according to a frequency change of the sweep signal; and obtaining the AC impedance according to a maximum value of the plurality of candidate AC impedances. 如申請專利範圍第1項所述的訊號增益控制方法，其中根據該交流阻抗與該直流阻抗獲得該增益調整值的步驟包括： 根據該交流阻抗與該直流阻抗之間的一差值獲得該增益調整值。The signal gain control method as described in item 1 of the patent application range, wherein the step of obtaining the gain adjustment value according to the AC impedance and the DC impedance includes: obtaining the gain according to a difference between the AC impedance and the DC impedance Adjust the value. 如申請專利範圍第3項所述的訊號增益控制方法，其中根據該交流阻抗與該直流阻抗之間的該差值獲得該增益調整值的步驟包括： 根據該直流阻抗獲得一初始增益調整值；以及 根據該初始增益調整值及該差值獲得該增益調整值。The signal gain control method as described in item 3 of the patent application scope, wherein the step of obtaining the gain adjustment value according to the difference between the AC impedance and the DC impedance includes: obtaining an initial gain adjustment value according to the DC impedance; And obtaining the gain adjustment value according to the initial gain adjustment value and the difference. 如申請專利範圍第1項所述的訊號增益控制方法，其中根據該交流阻抗與該直流阻抗獲得該增益調整值的步驟包括： 根據該直流阻抗調整該輸出訊號的一輸出電壓區間。The signal gain control method according to item 1 of the patent application scope, wherein the step of obtaining the gain adjustment value according to the AC impedance and the DC impedance includes: adjusting an output voltage interval of the output signal according to the DC impedance. 一種電子裝置，連接至一外接裝置，該電子裝置包括： 一交流阻抗偵測器，用以偵測該外接裝置的一交流阻抗； 一直流阻抗偵測器，用以偵測該外接裝置的一直流阻抗； 一訊號處理電路，連接至該交流阻抗偵測器與該直流阻抗偵測器並且用以根據該交流阻抗與該直流阻抗獲得一增益調整值；以及 一增益控制電路，連接至該訊號處理電路並且用以根據該增益調整值調整輸出至該外接裝置的一音訊訊號的一訊號增益。An electronic device is connected to an external device. The electronic device includes: an AC impedance detector for detecting an AC impedance of the external device; a DC impedance detector for detecting the duration of the external device Current impedance; a signal processing circuit connected to the AC impedance detector and the DC impedance detector and used to obtain a gain adjustment value according to the AC impedance and the DC impedance; and a gain control circuit connected to the signal The processing circuit is also used to adjust a signal gain of an audio signal output to the external device according to the gain adjustment value. 如申請專利範圍第6項所述的電子裝置，其中該交流阻抗偵測器偵測該外接裝置的該交流阻抗的操作包括： 發送一掃頻訊號，其中該掃頻訊號的頻率在一頻率範圍內變化； 根據該掃頻訊號的一頻率變化測得對應於該外接裝置的多個候選交流阻抗；以及 根據該多個候選交流阻抗的一最大值獲得該交流阻抗。The electronic device as described in item 6 of the patent application range, wherein the operation of the AC impedance detector to detect the AC impedance of the external device includes: sending a sweep signal, wherein the frequency of the sweep signal is within a frequency range Change; measure a plurality of candidate AC impedances corresponding to the external device according to a frequency change of the sweep signal; and obtain the AC impedance according to a maximum value of the plurality of candidate AC impedances. 如申請專利範圍第6項所述的電子裝置，其中該訊號處理電路根據該交流阻抗與該直流阻抗獲得該增益調整值的操作包括： 根據該交流阻抗與該直流阻抗之間的一差值獲得該增益調整值。The electronic device as described in item 6 of the patent application range, wherein the operation of the signal processing circuit to obtain the gain adjustment value according to the AC impedance and the DC impedance includes: obtaining based on a difference between the AC impedance and the DC impedance The gain adjustment value. 如申請專利範圍第8項所述的電子裝置，其中該訊號處理電路根據該交流阻抗與該直流阻抗之間的該差值獲得該增益調整值的操作包括： 根據該直流阻抗獲得一初始增益調整值；以及 根據該初始增益調整值及該差值獲得該增益調整值。The electronic device as described in item 8 of the patent application range, wherein the operation of the signal processing circuit to obtain the gain adjustment value according to the difference between the AC impedance and the DC impedance includes: obtaining an initial gain adjustment according to the DC impedance Value; and obtain the gain adjustment value according to the initial gain adjustment value and the difference. 如申請專利範圍第6項所述的電子裝置，其中該訊號處理電路根據該交流阻抗與該直流阻抗獲得該增益調整值的操作包括： 根據該直流阻抗調整該輸出訊號的一輸出電壓區間。The electronic device according to item 6 of the patent application scope, wherein the operation of the signal processing circuit to obtain the gain adjustment value according to the AC impedance and the DC impedance includes: adjusting an output voltage interval of the output signal according to the DC impedance. 如申請專利範圍第6項所述的電子裝置，其中該外接裝置為用以播放該音訊訊號的一音訊播放裝置。The electronic device as described in item 6 of the patent application range, wherein the external device is an audio playback device for playing the audio signal.
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